The objective of the proposed research is to synthesize a series of new bleomycins from an active ester of bleomycin acid in order to produce a tumor - localizing antibiotic with better metal binding capacity than the parent bleomycin. The preparation of the active ester of bleomycin acid has been prepared. In addition a derivative of DTPA has been developed which will react with the active ester of bleomycin. In addition DTPA can be reacted directly with the gamma amino group of the B-aminoalamine moiety of bleomycin. Hopefully this derivative will produce a bifunctional derivative which will have the biologic properties of bleomycin already demonstrated for 57Co directly labeled bleomycin and the nuclear properties of 99mTc. This product would fulfill the need for a sensitive tumor seeking radiopharmaceutical.